Royal Festival Hall, London
Until recently something of a novelty, percussion concertos seem nowadays to pop up at an alarming rate. Many are marred, however, by a combination of lack of direction and exhibitionist kitsch. Siedi, a new concerto by the Finnish composer Kalevi Aho commissioned by the Scottish percussionist Colin Currie in 2009, is different. The soloist's part is not without its technical difficulties, but the increasingly familiar parade of extravagant multi-instrument fireworks is replaced by something more sombre and germane.
The soloist never plays more than one instrument at a time, the work instead giving space to an exploration of the particular qualities of each. Starting with hand-beaten instruments – djembe and darabuka – the soloist moves across the stage through tom-toms, marimba and wood blocks, to the vibraphone and tam-tam, at which point the orchestra is engulfed in a kind of collective shimmering. The soloist then moves back across the instruments.
The ideas are mostly simple and undulating, with measured repetitions conferring a sense of ritual (Siedi is, in fact, a Sami word for a sacred rock or mountain). The skill with which the soloist's material is amplified and transformed through the orchestra adds to a sense of wonder that grows steadily over nearly 40 minutes. After a rippling tom-tom roll – the closest the work comes to polyrhythmic fireworks – the piece doesn't so much end as evaporate, diffusing through a quiet colloquy of djembe, muted trumpets, wood blocks and, finally, gourds. The effect is of losing consciousness while being conscious of doing so, like seeing particles of awareness crystalise and disperse into shadow.
Currie and the London Philharmonic performed the work beautifully, led by Aho's compatriot Osmo Vänskä. The rest of the programme, comprising Schumann's Genoveva overture and Brahms' first symphony, was less impressively handled and – surprisingly given the distinguished conductor – was at times worryingly scrappy.
• Available on BBC iPlayer until 25 April.
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